Lineally-expansible thermostat for melting pots of type setting machines



Feb. 20, 1962 E. VILLARREAL 3,022,404

LINEALLY-EXPANSIBLE THERMOSTAT FOR MELTING POTS OF TYPE SETTING MACHINES Filed Aug. 22, 1960 IN VEN TOR. ENRIOUE VILLA RREAL ATTORNEY United States l atent Ofitice 3,0214% Patented Feb. 20, 1962 3,022,404 LINEALLY EXPANSIBLE THERMGSTAT F011 MELTING PUTS OF TYPE SETTING MACHLNES Enrique Villarreal, Monelova 47 (Col. Roma-Stir), Mexico City, Mexico Filed Aug. 22, 196i), Ser. No. 51,123 Claims. (Cl. 200-137) This invention relates to a lineally-expansible thermostat for use in melting pots of type setting machines.

It is the principal object of the present invention to provide a thermostat for use in melting pots of type setting machines which is sensitive and will maintain the metal at a constant temperature with little deflection therefrom.

It is another object of the invention to provide a thermostat for controlling the temperature of type metal in a melting pot and for other uses, which can be easily and readily adjusted to vary the temperature at which the metal is to be maintained.

It is still another object of the invention to provide a thermostat operating on mechanical principles which will be as sensitive as magnetic relay type thermostats and by which the lineal expansion of thermal parts is mechanically magnified and the switch opened and closed instantly by slight deviations of the lineal parts.

It is a further object of the invention to provide a mechanically operable magnifying mechanism for thermostats that will make a quick break and closure for switches for slight deviation in the expansion of the lineal parts and in which a diaphragm will be employed to fiex instantaneously under a slight pressure imparted thereto by which the switch contacts will be opened and closed quickly.

it is a still further object of the invention to provide in a diaphragm operated switch for thermostats multiple contacts associated therewith to minimize the arcing of the electric current between the contacts as they are broken.

Other objects of the invention are to provide a lineallyexpansible thermostatic switch, having the above objects in mind, which is simple in construction, has a minimum number of parts, compact, durable, easy to install, maintain and adjust, efficient and eifective in operation.

For a better understanding of the invention, reference may be had to the following detailed description taken in connection with the accompanying drawing, in which- FIGURE 1 is a front elevational view of the typesetting melting pot thermostat embodying the features of the present invention,

FIG. 2 is a fragmentary side elevational view of the present thermostat, the lower part of the linear expansible elements being cut away, and

FIG. 3 is a fragmentary rear elevational view of the thermostat with the lower part of the linear elements cut away.

Referring now to the figures, It represents a central linear expansible rod that is concentrically disposed within a linear-expansible tube 11 having windows 12 near its lower end to permit molten-type metal to enter the tube and contact the rod as well as the tube. The tube has a coefiicient of expansion of the type metal so as to expand therewith while the central rod may have a different coefiicient of expansion. The lower end of the rod 10 extends through a hole '13 in the lower end of the tube by a nut 14 threaded thereon, and abutting the under end face of the tube 11 supports the tube 11 against downward displacement relative thereto. The upper end of the rod 10 is threaded as indicated at 15 and is secured to a double bridge assembly by locked nuts 16 and 17 formed of a lower metal part 18 that is fixed to a metal thermostat base 19 by screws 19 part 24) that is made of insulating material and is generally LJ-shaped. The upper end of the tube 11 is provided with a ring 21 adapted to be lifted the expansion of the tube 11 and through which the upper end of the rod 10 passes. This ring 21 has a diametrica1ly-extending slot 23 extending from the front to the rear. Within this slot 23 is a substantially L-shaped piece 24 having a thick horizontal portion and a short vertical portion 25. The piece 24 is transversely connected by its portion 25 and within the slot 23 of the ring to the sides of the ring 21 by a pin 26, FIG. 2. As the tube 11 expands to a greater amount than the rod 10, the ring 21 is lifted by the tube 11.

On the horizontal portion of the L-shaped piece 24, there is rested an adjustable screw 27 that is adjusted to set the thermostat to the desired temperature of the melted type material which the thermostat is to maintain. This adjustable temperature-setting or regulating screw 27 is supported on a transversely-extending metal memher or cross piece '26 connected between the upper ends of two opposing resilient angle-shaped members 29 fixed by screws 29 to the front face of the lower bridge part 18 that is fixed to the thermostat base 19 by the screws 19'. This transversely-extending member 28 has a screw 30 which is tightened to fix the adjusting screw 27 in its adjusted position.

At the middle of the transversely-extending member or cross piece 28 there is connected a vertically-extending bar assembly 31 by a fastening screw 31 extending into its lower end. The upper end of the vertically-extending bar assembly 31 carries an insulating bar 32 made secure thereto by screws 32' and which has a vertically-extending slot 33 through which a position-fixing screw 34 is extended to secure an insulated cylindrical shaped member 35 in a vertica1ly-adjusted position upon the verticallyextending insulating member'32. The inner end of the insulating cylindrical member, as the bar assembly 31 is elevated through a U-shaped guide 36 fixed to the bridge block 29 by screws 36" resulting from the difference in expansion of the rod 10 and tube 11 that will have been submerged in the molten metal, stresses a metallic diaphragm 36 in a manner to be later described for the purpose of opening switch contacts and to disconnect the heating element for the molten metal (not shown), but which is being controlled by the thermostat. The diphragm is a thin metallic, radially-flexible plate and is fixed to the upper insulating U-shaped bridge block by respective screws 37 and 3S threaded into the respective side branches 39 and 40 thereof. The lower end of the diaphragm 36 rests against horizontal shoulders 41 and to 'an upper bridge upon steps 41' of the insulating block. The upper end of the diaphragm 35 extends over upon top lips or shoulders 42 and 43 and extends upwardly therebeyond. A plurality of weakening holes 44 is provided in the form of a circle in the diaphragm to'facilitate the fiexure of the diaphragm. Fixed to the upper end of the diaphragm are three later-ally spaced contacts 45, 46 and 47, FIG. 1, that extend forwardly for engagement with respective contacts 45', 46' and 47", FIG. 3, that are carried on a W- shaped vertically-extending opposing metal plate 48 that is secured to the opposite face of the insulating bridge block by fastening screws 49 and 50. Through these multiple cont-acts the heating current for the electric heater in the type metal pot is supplied. The plate 43 is connected to the terminal 51 while the diaphragm 36 is connected from the terminal 51 to a lamp socket 53 having a neon signal lamp 54 therein and the other terminal of the socket 53 is connected by a conducting strip 52' with the terminal 52. In this manner, the neon lamp 54 is placed in shunt or parallel relationship with the contacts 45--45', 46--46' and 47-47. The terminal 52 is connected in series with a fuse 55 detachably carried by a fuse holder 56 mounted upon the rear face of a metallic backplate 57 that is supported and made secure to a metallic cross piece 58 by fastening screws 59. The terminals 51 and 52 are insulatingly supported upon the vertically-extending backplate 57.

A temperature scale 60 is engraved in the front face of the metallic backplate 57, FIG. 1, over which a needle pointer 61 passes to indicate the temperature of the molten type metal. This needle pointer is pivotally connected to the cross piece 58 by a pivot pin 63 and carries a small plate 64 having an end projection that engages free end 66 of a small pivot arm 67 pivotally connected to the cross piece 58 by a pin 63, FIG. 3. The pivot arm 67 rests intermediate its length on the upper end of a piece 69 vertically-adjustable in a sleeve guide 7% carried on the cross piece 58, FIG. 2. A regulating screw 71 for the pointer 61 is adjustably carried on the lower end of the vertically-adjustable piece 69 so that its head 72 rests upon the ring 21 whereby the needle pointer will be worked by the differential movement of the tube 11. The needle pointer is biased toward its zero degree indication by a tension spring 73 connected between the needle and the cross piece 58, FIG. 3.

In operation, the rod 10 and the tube 11 are disposed in the type metal so that as the metal begins to melt the heat causes the tube 11 to expand upwardly greater than the rod 28 so that the ring 21 acts upon the pivot block 24 and the needle regulating screw head 72. to lift the vertically-extending bar assembly 31 and deflect the needle pointer 61. The adjustable screw 27 engages the pivot block 24 through which the bar assembly 31 is lifted.

The cylindrically shaped projection member 35 on the bar assembly 31 bears against the diaphragm 36 and upon moving upwardly rubs its end against the face of the diaphragm and toward the shoulders 42 and 43 of the upper bridge member portions 39 and 48 of the bridge member to deflect outwardly the upper end of the diaphragm 36 and its contacts 45, 46 and 47 from the contacts 45', 46 and 47 of the upwardly extending plate 48 in a manner illustrated by the dotted lines of FIG. 2. When the temperature is lowered in the type metal, the bar assembly 31 and the cylindrical shaped member 35 carried thereby is lowered to allow the diaphragm 36 to assume its original shape shown in full lines in FIG. 2 so that the electric heater within the type metal is again energized to bring type metal again to a desired temperature as determined by the adjustable screw 27 that supports the bar assembly 31 on the pivot block 24. The diaphragm 36 has in eliect in it'a small lever acting with its fulcrum over the shoulders 4-2 and 43 at the upper ends of the upper bridge block 20.

The ring 21 on the tube 11 also through its engagement with the regulating screw head 72 lifts the piece 69 through the guide sleeve 7% and the pivot arm 67 that acts against the fixed plate 64 at the root of the needle 61 to pivot it upon its pivot pin 63 and cause an indication to be made upon the scale 60 of the backplate 57.

It should now be aparent that there has been provided a thermostat adapted for use in controlling the heater current of a type metal melting pot which is sensitive to differences in temperature of the type metal and which can be regulated to diflerent temperature settings and which as well as opening and closing the switch gives needle temperature indications and a light from a neon lamp to indicate whether or not the electric current is being supplied by its glow.

While various changes may be made in the detailed construction, it shall he understood that such changes shall be within the spirit and scope of the present invention as defined by the appended claims.

What is claimed is:

1. A lineal expansible thermostat adapted for use in melting pots of type setting machines to control the heater current supplied to the molten type material, comprising a base, a bridge support mounted upon the base, a rod fixed to the bridge support and suspended through the base, a tube surrounding the rod and supported upon the lower end thereof and adjustable through the base, a vertically-extending flexible diaphragm secured to the bridge support to be flexed thereover, a vertically-extending bar assembly vertically-slidable upon the bridge support and having a member projecting horizontally from the bar assembly and adapted to rub vertically over the diaphragm to flex the diaphragm, means extending between the tube and the bar assembly to vertically move the bar assembly in response to the lineal expansion of the tube, said diaphragm having contacts adapted to be moved laterally upon the diaphragm being flexed, a fixed contact carried on the bridge support and engaged when the diaphragm is unflexed by the contacts of the diaphragm, said operating means for the vertically extending bar assembly having a laterally-extending piece and a ring supporting said laterally extending piece and carried upon the upper end of the tube, an adjusting screw carried by the vertically-extending bar assembly and adapted to be engaged by the laterallyextending piece.

2. A lineal expansible thermostat adapted for use in melting pots of type setting machines to control the heater current supplied to the molten type m aterial, comprising a base, a bridge support mounted upon the base, a rod fixed to the bridge support and suspended through the base, a tube surrounding the rod and supported upon the lower end thereof and adjustable through the base, a vertically-extending flexible diaphragm secured to the bridge support to be flexed thereover, a vertically-extending bar assembly vertically-slidable upon the bridge support and having a member projecting horizontally from the bar assembly and adapted to rub vertically over the diaphragm to flex the diaphragm, means extending between the tube and the bar assembly to vertically move the bar assembly in response to the lineal expansion of the tube, said diaphragm having contacts adapted to be moved laterally upon the diaphragm being flexed, a fixed contact carried on the bridge support and engaged when the diaphragm is uniiexed by the contacts of the diaphragm, said bar assembly including an inverted c -shaped member raving a vertically-extending slot, and sa d horizontally projecting member being adjustable in said support and means on the horizontally projecting member for retaining the member in its verticallyadjusted position in the slot.

3. A lineal expansible thermostat adapted for use in meltlng pots of type setting machines to control the heater current supplied to the molte i type material, comprislng a base, a bridge support mounted upon the base, a rod fixed to the bridge support and suspended through the base, a tube surrounding the rod and supported upon the lower end thereof and adjustable through the base, a yertically-extending flexible diaphragm secured to the bridge support to be flexed thereover, a vertically-extendmg bar assembly vertically-slidable upon the bridge support and having a member projecting horizontally from the bar assembly and adapted to rub vertically over the diaphragm to flex the diaphragm, means extending between the tube and the bar assembly to vertically move the bar assembly in response to the lineal expansion of the tube, said diaphragm having contacts adapted to be moved laterally upon the diaphragm being flexed, a fixed contact carried on the bridge support and engaged when the diaphragm is unflexed by the contacts of the diaphragm, a back plate secured to the bridge support, and terminal connections extending from the diaphragm and the fixed contacts to the back plate, and a neon signal light socket connected between the terminal connections in shunt relationship therewith.

4. A lineal expansible thermostat adapted for use in melting pots of type setting machines to control the heater current supplied to the molten type material, comprising a base, a bridge support mounted upon the base, a rod fixed to the bridge support and suspended through the base, a tube surrounding the rod and supported upon the lower end thereof and adjustable through the base, a vertically-extending flexible diaphragm secured to the bridge support to be flexed thereover, a vertically-extending bar assembly vertically-slidable upon the bridge support and having a member projecting horizontally from the bar assembly and adapted to rub vertically over the diaphragm to flex the diaphragm, means extending between the tube and the bar assembly to vertically move the bar assembly in response to the lineal expansion of the tube, said diaphragm having contacts adapted to be moved laterally upon the diaphragm being flexed, a fixed contact carried on the bridge support and engaged when the diaphragm is unflexed by the contacts of the diaphragm, a needle pointer, a back plate secured to the bridge support means for pivotally connecting said pointer upon the bridge support, said pointer extending upwardly over the forward face of the back plate, and said back plate having a temperature scale over which the needle pointer may extend to give indications of the temperature of the molten metal, a pivot arm mounted on the bridge support and engageable with said needle pointer to operate the same, a member including an adjusting screw depending from said pivot arm and engageable with said tube whereby said needle will be worked by the lineal expansion of said tube.

5. A lineal expansible thermostat adapted for use in melting pots of type setting machines to control the heater current supplied to the molten type material, comprising a base, a bridge support mounted upon the base, a rod fixed to the bridge support and suspended through the base, a tube surrounding the rod and supported upon the lower end thereof and adjustable through the base, a vertically-extending flexible diaphragm secured to the bridge support to be flexed thereover, a. vertically-extending bar assembly vertically-slidable upon the bridge support and having a member projecting horizontally from the bar assembly and adapted to rub vertically over the diaphragm to flex the diaphragm, means extending between the tube and the bar assembly to vertically move the bar assembly in response to the lineal expansion of the tube, said diaphragm having contacts adapted to be moved laterally upon the diaphragm being flexed, a fixed contact carried on the bridge support and engaged when the diaphragm is unfiexed by the contacts of the diaphragm, said means for operating the bar assembly including a ring carried by the upper end of the tube, and having a laterally-extending piece, adjustable means on the bar assembly engageable by the laterally-extending piece on the ring member, a needle pointer pivotally mounted upon the bridge support, and a pivot arm on the bridge support engageable with the pointer to operate the same and a depending operating piece engageable by said ring to efiect the actuation of the pointer.

References Cited in the file of this patent UNITED STATES PATENTS 889,355 Brown June 2, 1908 1,780,758 Leupold Nov. 4, 1930 2,630,479 Villarreal Mar. 3, 1953 FOREIGN PATENTS 19,906 Great Britain Mar. 4, 1909 of 1908 

